Towards testing of identity concepts in horses: conditional discrimination learning

Abstract: Experiments have shown that horses are capable of some types of discrimination learning and that they can learn the concept of relative size, but it is unknown whether horses can select a test stimulus by similarity to a sample stimulus. In this project, four horses failed to learn a two choice matching-to-sample task without a mechanism that ensured that they paid attention to the sample stimulus. Learning performances for conditional discrimination tasks, with similarities to the original matching-to-sample task, were also investigated and one horse was successful in learning such a task. These results point out interesting aspects of the horses' learning behaviors, but more research is needed to investigate the validity of the observed trends.